Headless Blender using Cycles without X-server?
It has been a while but I have rendered on a headless machine. I did have Xorg installed to be able to run x11 apps remotely but the was no running X-server on the remote machine.

If you want to get blender running without any X-server software installed then you will most likely have to compile your own version of blender. There is an option to build WITH_HEADLESS that will disable all dependencies on Xorg libraries.